Thermoacoustic performance of 100 kHz wide-band packaged projector in water tank with three-dimensional graphene

Abstract

This paper presents the demonstration of underwater thermoacoustic (TA) sound generation using three-dimensional graphene (3D-C). 3D-C is able to interface with water as the immediate acoustic medium, resulting in reduced attenuation across solid packaging encapsulation due to favorable acoustic impedance matching. This is shown using array configurations of 2*2 and 4*4 individual 3D-C elements prepared onto printed circuit boards and secured within a watertight cuboid Delrin container with deionized water. Comparisons of underwater acoustic performance between internal medium of water and air shows significant improvement in measured sound pressure level (SPL) with internal water medium, in contrast with internal air medium where SPL were below noise floor. This demonstration opens up new possibilities of 3D-C for underwater acoustic applications. Simulations are conducted using 3D finite element model generated with COMSOL Multiphysics and validated with experimental results. A revised formulation of transmission voltage response (TVR) specific to TA sound generation is proposed due to the difference in power scaling of TA sound generation and subsequently validated using simulation.

Keywords:

• Experimental validation
• finite element method
• simulation
• thermoacoustic
• three-dimensional graphene
• transmission voltage response

Disclosure statement

The authors declare that there is no conflict of interest.

Additional information

Funding

This work was supported by Future Systems & Technology Directorate at the Ministry of Defence, Singapore. Phonon Pte Ltd had also supported this work in terms of sample fabrication.